A split gate MOSFET(SG-MOSFET)is widely known for reducing the reverse transfer capacitance(C_(RSS)).In a 3.3 kV class,the SG-MOSFET does not provide reliable operation due to the high gate oxide electric field.In add...A split gate MOSFET(SG-MOSFET)is widely known for reducing the reverse transfer capacitance(C_(RSS)).In a 3.3 kV class,the SG-MOSFET does not provide reliable operation due to the high gate oxide electric field.In addition to the poor static performance,the SG-MOSFET has issues such as the punch through and drain-induced barrier lowering(DIBL)caused by the high gate oxide electric field.As such,a 3.3 kV 4 H-SiC split gate MOSFET with a grounded central implant region(SG-CIMOSFET)is proposed to resolve these issues and for achieving a superior trade-off between the static and switching performance.The SG-CIMOSFET has a significantly low on-resistance(R_(ON))and maximum gate oxide field(E_(OX))due to the central implant region.A grounded central implant region significantly reduces the C_(RSS)and gate drain charge(Q_(GD))by partially screening the gate-to-drain capacitive coupling.Compared to a planar MOSFET,the SG MOSFET,central implant MOSFET(CIMOSFET),the SGCIMOSFET improve the R_(ON)×Q_(GD)by 83.7%,72.4%and 44.5%,respectively.The results show that the device features not only the smallest switching energy loss but also the fastest switching time.展开更多
For the case that two pursuers intercept an evasive target,the cooperative strategies and state estimation methods taken by pursuers can seriously affect the guidance accuracy for the target,which performs a bang For ...For the case that two pursuers intercept an evasive target,the cooperative strategies and state estimation methods taken by pursuers can seriously affect the guidance accuracy for the target,which performs a bang For the case that two pursuers intercept an evasive target,the cooperative strategies and state estimation methods taken by pursuers can seriously affect the guidance accuracy for the target,which performs a bang-bang evasive maneuver with a random switching time.Combined Fast multiple model adaptive estimation(Fast MMAE)algorithm,the cooperative guidance law takes detection configuration affecting the accuracy of interception into consideration.Introduced the detection error model related to the line-of-sight(LOS)separation angle of two interceptors,an optimal cooperative guidance law solving the optimization problem is designed to modulate the LOS separation angle to reduce the estimation error and improve the interception performance.Due to the uncertainty of the target bang-bang maneuver switching time and the effective fitting of its multi-modal motion,Fast MMAE is introduced to identify its maneuver switching time and estimate the acceleration of the target to track and intercept the target accurately.The designed cooperative optimal guidance law with Fast MMAE has better estimation ability and interception performance than the traditional guidance law and estimation method via Monte Carlo simulation.展开更多
This paper mainly introduces the design and research of plant cultivation device in intelligent agricultural greenhouse.The device can automatically ventilate and control the temperature when the carbon dioxide conten...This paper mainly introduces the design and research of plant cultivation device in intelligent agricultural greenhouse.The device can automatically ventilate and control the temperature when the carbon dioxide content is insufficient.At the same time,the light color can be selected according to the plant properties,and the light and dark time can be controlled to provide a suitable growth environment for plants,which makes up for the shortcomings of the existing ordinary greenhouse.With China's strong support for agriculture,automatic agriculture is developing rapidly,and has a broad market prospect.展开更多
We investigate properties of perpendicular anisotropy magnetic tunnel junctions(pMTJs) with a stack structure MgO/CoFeB/Ta/CoFeB/MgO as the free layer(or recording layer),and obtain the necessary device parameters fro...We investigate properties of perpendicular anisotropy magnetic tunnel junctions(pMTJs) with a stack structure MgO/CoFeB/Ta/CoFeB/MgO as the free layer(or recording layer),and obtain the necessary device parameters from the tunneling magnetoresistance(TMR) vs.field loops and current-driven magnetization switching experiments.Based on the experimental results and device parameters,we further estimate current-driven switching performance of pMTJ including switching time and power,and their dependence on perpendicular magnetic anisotropy and damping constant of the free layer by SPICE-based circuit simulations.Our results show that the pMTJ cells exhibit a less than 1 ns switching time and write energies <1.4 pJ;meanwhile the lower perpendicular magnetic anisotropy(PMA) and damping constant can further reduce the switching time at the studied range of damping constant α <0.1.Additionally,our results demonstrate that the pMTJs with the thermal stability factor■73 can be easily transformed into spin-torque nano-oscillators from magnetic memory as microwave sources or detectors for telecommunication devices.展开更多
Simultaneous wireless information and power transfer(SWIPT)is recently emerging as one of the vital solutions to prolong the lifetime of energy constrained wireless sensor nodes.However,current works on SWIPT consider...Simultaneous wireless information and power transfer(SWIPT)is recently emerging as one of the vital solutions to prolong the lifetime of energy constrained wireless sensor nodes.However,current works on SWIPT considered only the immediate past-hop node’s RF signal as a source of energy harvesting in multi-hop Internet of things(IoT)networks.In case of weak radio frequency(RF)signal,the amount of harvested energy does not support for continuous communication.Hence,in this paper a new energy harvesting mechanism is proposed which considers multiple sources(MS)such as(1)sink broadcasting energy,(2)co-channel interference,(3)neighbor nodes’RF signal,and(4)immediate past-hop node’s RF signal for energy harvesting.Towards such prospect,a new SWIPT architecture is proposed called hybrid SWIPT(H-SWIPT)by integrating time switching(TS)and power splitting(PS)architectures.Furthermore,an efficient route selection mechanism is introduced to minimize the total energy consumption of the path based on an energy cost metric.To validate the proposed mechanism,simulation experiments are conducted and obtained the superiority of H-SWIPT compared with existing methods in terms of average harvested energy.Further,the effectiveness of proposed method performance is investigated through energy cost at different node density and barrier rates.展开更多
基金supported by the MSIT(Ministry of Science and ICT),Korea,under the ITRC(Information Technology Research Center)support program(IITP-2020-2018-0-01421)supervised by the IITP(Institute for Information&communications Technology Promotion)then Samsung Electronics.
文摘A split gate MOSFET(SG-MOSFET)is widely known for reducing the reverse transfer capacitance(C_(RSS)).In a 3.3 kV class,the SG-MOSFET does not provide reliable operation due to the high gate oxide electric field.In addition to the poor static performance,the SG-MOSFET has issues such as the punch through and drain-induced barrier lowering(DIBL)caused by the high gate oxide electric field.As such,a 3.3 kV 4 H-SiC split gate MOSFET with a grounded central implant region(SG-CIMOSFET)is proposed to resolve these issues and for achieving a superior trade-off between the static and switching performance.The SG-CIMOSFET has a significantly low on-resistance(R_(ON))and maximum gate oxide field(E_(OX))due to the central implant region.A grounded central implant region significantly reduces the C_(RSS)and gate drain charge(Q_(GD))by partially screening the gate-to-drain capacitive coupling.Compared to a planar MOSFET,the SG MOSFET,central implant MOSFET(CIMOSFET),the SGCIMOSFET improve the R_(ON)×Q_(GD)by 83.7%,72.4%and 44.5%,respectively.The results show that the device features not only the smallest switching energy loss but also the fastest switching time.
基金This work was supported by the National Natural Science Foundation(NNSF)of China under grant no.61673386,62073335the China Postdoctoral Science Foundation(2017M613201,2019T120944).
文摘For the case that two pursuers intercept an evasive target,the cooperative strategies and state estimation methods taken by pursuers can seriously affect the guidance accuracy for the target,which performs a bang For the case that two pursuers intercept an evasive target,the cooperative strategies and state estimation methods taken by pursuers can seriously affect the guidance accuracy for the target,which performs a bang-bang evasive maneuver with a random switching time.Combined Fast multiple model adaptive estimation(Fast MMAE)algorithm,the cooperative guidance law takes detection configuration affecting the accuracy of interception into consideration.Introduced the detection error model related to the line-of-sight(LOS)separation angle of two interceptors,an optimal cooperative guidance law solving the optimization problem is designed to modulate the LOS separation angle to reduce the estimation error and improve the interception performance.Due to the uncertainty of the target bang-bang maneuver switching time and the effective fitting of its multi-modal motion,Fast MMAE is introduced to identify its maneuver switching time and estimate the acceleration of the target to track and intercept the target accurately.The designed cooperative optimal guidance law with Fast MMAE has better estimation ability and interception performance than the traditional guidance law and estimation method via Monte Carlo simulation.
文摘This paper mainly introduces the design and research of plant cultivation device in intelligent agricultural greenhouse.The device can automatically ventilate and control the temperature when the carbon dioxide content is insufficient.At the same time,the light color can be selected according to the plant properties,and the light and dark time can be controlled to provide a suitable growth environment for plants,which makes up for the shortcomings of the existing ordinary greenhouse.With China's strong support for agriculture,automatic agriculture is developing rapidly,and has a broad market prospect.
基金Project supported by State Grid Corporation of China under the 2018 Science and Technology Project of State Grid Corporation:Research on electromagnetic measurement technology based on EIT and TMR(Grant No.JL71-18-007)。
文摘We investigate properties of perpendicular anisotropy magnetic tunnel junctions(pMTJs) with a stack structure MgO/CoFeB/Ta/CoFeB/MgO as the free layer(or recording layer),and obtain the necessary device parameters from the tunneling magnetoresistance(TMR) vs.field loops and current-driven magnetization switching experiments.Based on the experimental results and device parameters,we further estimate current-driven switching performance of pMTJ including switching time and power,and their dependence on perpendicular magnetic anisotropy and damping constant of the free layer by SPICE-based circuit simulations.Our results show that the pMTJ cells exhibit a less than 1 ns switching time and write energies <1.4 pJ;meanwhile the lower perpendicular magnetic anisotropy(PMA) and damping constant can further reduce the switching time at the studied range of damping constant α <0.1.Additionally,our results demonstrate that the pMTJs with the thermal stability factor■73 can be easily transformed into spin-torque nano-oscillators from magnetic memory as microwave sources or detectors for telecommunication devices.
文摘Simultaneous wireless information and power transfer(SWIPT)is recently emerging as one of the vital solutions to prolong the lifetime of energy constrained wireless sensor nodes.However,current works on SWIPT considered only the immediate past-hop node’s RF signal as a source of energy harvesting in multi-hop Internet of things(IoT)networks.In case of weak radio frequency(RF)signal,the amount of harvested energy does not support for continuous communication.Hence,in this paper a new energy harvesting mechanism is proposed which considers multiple sources(MS)such as(1)sink broadcasting energy,(2)co-channel interference,(3)neighbor nodes’RF signal,and(4)immediate past-hop node’s RF signal for energy harvesting.Towards such prospect,a new SWIPT architecture is proposed called hybrid SWIPT(H-SWIPT)by integrating time switching(TS)and power splitting(PS)architectures.Furthermore,an efficient route selection mechanism is introduced to minimize the total energy consumption of the path based on an energy cost metric.To validate the proposed mechanism,simulation experiments are conducted and obtained the superiority of H-SWIPT compared with existing methods in terms of average harvested energy.Further,the effectiveness of proposed method performance is investigated through energy cost at different node density and barrier rates.